Field of the Invention
In many situations, it is found that the lachrymal film is discontinuous. This can be a result of weak lachrymal films, as inadequate rate of blinking, or with some users, wearing of contact lenses. There is, therefore, a need to provide a synthetic tear which can act as a tear substitute for dry eye syndromes. In addition, solutions which would provide stable ocular films could be used for prolonging the precorneal tear film retention of drugs instilled in liquid ophthalmic vehicles and for the wetting and cushioning of contact lenses.
Description of the Prior Art
Benedetto, Shah and Kaufman, Investigative Ophthalmology 14, 887 (1975) describes testing of hydroxypropylmethylcellulose and polyvinyl alcohol to prolong precorneal tear films.